In general, construction machinery such as a wheel type excavator or a wheel loader changes a traveling direction by supplying working oil, which is discharged from a pump, to a steering actuator. More specifically, when an operator manipulates a steering handle, a steering unit discharges the working oil at a flow rate proportional to a rotational speed of the steering handle, the working oil is supplied to the steering actuator through a steering valve, and as a result the steering actuator moves a traveling apparatus to perform a steering operation.
However, when abnormality of a hydraulic circuit occurs or construction machinery of electronic equipment is not normally operated, because a discharge flow rate may not be adjusted by both steering actuators, such that there is a concern that safety of the operator may be at risk and damage of the equipment and an accident may occur.
Therefore, development is required on an emergency steering apparatus for construction machinery having an emergency steering apparatus capable of protecting the operator and the equipment when a flow rate of the working oil is not controlled due to abnormality of each part.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.